Heater for enclosed spaces



Sept. 23, 1952 c. D. M cRAcKEN 2,611,599

.i-IFATER FOR ENCLOSED SPACES Filed May 18, 1948 4 Sheet s-Sheet 1 JNKENTOR. +CO/V/I7D MacGracke/r A flamers Sept. 23, 1952 c. D. M CRACKEN 2,611,599

' HEATER FUR ENCLOSED SPACES Filed May 18, 1948 4 Sheets-Sheet 2 g] l g 9% F/GZ IN V EN TOR.

Ca/v/h 0. Mac Grac/ren 224 ra Afforneys Sept. 23, 1952 c. D. M CRACKEN HEATER FOR ENCLOSED SPACES 4 Sheets-Sheet 3 Filed May 18, 1948 INVENTOR.

.Ca/w'n 0. Mac Grac/ren A fom eys Sept. 23, 1952 I c. D. M CRACKEN 2,611,599

HEATER FOR ENCLOSED SPACES Filed May 18. 1948 4 Sheets-Sheet 4 INVENTOR. Calvin 0. MacCrac/ren ram Attorneys Patented Sept. 23,1952

UNIT-ED S as a V "'HEATER FQRENCLOsEiiSPKCES f v Calvin n.- MacCracken, New Reagent-m; Yea r signer to Jet-Beet, Inca'NW -ECorE; N. Y xa corporation of New York Application May is, 19485Srial'hlo i273162 1 f v "This inventionrelates' to heaters forvenclosed spaces; The general objector the invention is to provide a heater, preferably intended to be located within the enclosed space, which will sup ly to that space a mixture of'hot gaseous products of combustion and air of which at'least'a portion is rawn from'outside that space, preferably from out-of-doors. Theinventi'oii is particularly useful and is hereinafter describedg-as embodie'd'in tobacco-barn heater'sj butfitwillbe understood 'thatit may be embodied in heaters-fer supplying amixture of hot aimnd'gaseeus produets'ci com bustioh'toanlenclos'ed space of any kindusedror ll? P11115058} which is to bereaved; temporarily oif 'fol" ah extended peridd of time to a: high tempara-tum, say 150 to 20W" Fl Whefi the invehtion is embodied in a tobaccobarn'hater, it notomy supplies mine barn'la mixture of hotair and gaseous products of combustion; but will produce nd gasee so that tobacco hun upfwithin the barn will be, rapidly} efficiently and unifcirn'il i, cured at desiredtemperature without fire risk; a

' Thev fuel employed in theiembodiinnts of the invention hereinafter described is preferably oil,

but ar c natu al smey e s d air needed for combustion' of the fuel, and the circulation of the-hotproducts of combustion and heated air,- are supplied by anelectrically-driven fan. Not only is out-of-doors air supplied to the he by t e n b tmane d aws i rom within the barn and supplies it to the heater,

A1'tliough.the highest temperature of the air and gaseous proclucts of combustion supplied by the heaterimav teas high as perhaps 1200 all dangefof'fire due'to tobacco leaves fallingon the heateriis eliminated by reason of the fact that all .ortnej 'arts of the heate'r whichc'arry the not gaseousproducts of combustion and air'aren- .close'dwithin casings and pipes throughwhich coo lerair is" circulated;

The various adv nta ges of the heater ap .pear from the following description of itsconstruction, taken inco'rinection with th'e 'acc'ompanying drawings, in which Fig. .1 i sa side elevation, partlyin section, of a heateroeinbodyin g the invention located within a tobaccobarn'; Fig 2 is a sectional elevation of another form of the .heaterembodying the invention; Fig.3is a plan View of the heater shown'in Fig. 2, the walls of the barn being indicated'in seotion; Fig e is a vsectional elevation of still another form of heater embodying'the invention; and Fig. 5 a frag} me ntary view of a portion ofthewall of the com bustion chamber, showing the small holes therein.

proper circulation within theb arnbt 'the'hot air I 4 Claims. (Clix 263 19) ing surround the distributingviiipes'qiifihe The embodimentbi the-invemion illustrated inlFig'. 1 will first-be described. -In that fig ure", the heater *is' shownas located on the fiecr 1 a of {a tobacco tam in which the tobacco leaves-1 2 to be cured are shown suspended in a usualway which issupported a combustion chamber 32" the construction and iurrctioning of which will be hereinafter described; MQ'u'nted in thebottom of the combustion chamber 3'2 is afuel noz'zle- 34;; and 'an'ignitionfdevice, suchjas'a s'park plug 36,

'is'mounted inth e'combustion chamber; as shown.

Itw'iIlbefno-ted that the casing Biljis spaced away rfr'om the' combustion chamber '32 ,"thereby providine," an'annular space throughwhiohairpasses iromlthe" fan 26. 'Coop'erating with the top 'of the combustion chamber 7 32 is an inner casing or Iniaiiifold '40 which receives from'fthe combustion c amber 32 the hot gaseous products of combustionjarid dilutirig' air mixedtherewithz" connected ta; the manifold 40' are a plurality of distributin'g. pipes 42 which extend outwardly-from the manifold and. carry the mixture of hot air and gaseous products of combustion to'the downwaruiy directed ends'M-offthe distributing pipes "42. I A casing 46 surrounds the" manifold *4 Sand is supported on the top offthe' casing 38 which surrounds the lcombustion chamber 32 v An I ant war space'isprovided'between the casing 4e and the top or the casing .30;"throughwhich air supplied by the iaii 25: may" flow" mm; the space within the iiianifoldcasing c nnectee te the 't'opf of themamreld casing ie is amp-e 5a; which extends upwardiy and'outwardiy I is"coh t'- ed to a'downwardly extendin 1 1p e 52 com'niu mating with a imn'zontany' arranged pipejfl leading to the'fanjcasing' 28. The" pipei s'a is preferably provided with extension .56 conta'mmg damper \58'fb'y] which the a mission or air to theip'i'pe SMnaY'beLregmated; casing pipes 60' extending from the mandatesreby providing annular 'passages'betweea the d trib uting pipes 42 and the encasing' pipes "60.

Through these annular passages flow barn air which enters the encasing pipes 60 at their hooded ends 62 surrounding the downwardly extending ends 44 of the pipes 42. For a purpose hereinafter explained, the encasing pipes 60 are preferably provided with openings which may be located at various places and in Fig. 1 are indicated at 64 near the points where the encasing pipes 60 are connected to the manifold casing 46. The manner in which the distributing pipes 42 and their encasing pipes 60 extend outwardly from the heater will be apparent from Fig. 3 although that figure is a plan view of the embodiment of the invention particularly illustrated in Fig. 2 and hereinafter described. Fuel oil or gas is supplied to the fuel nozzle 34 through the pipe 66 from any suitable oil pump (not, shown) which may be driven by the motor 22 or otherwise; and the spark plug 36 is connected by a wire 68 to any suitable and well-known ignition device which is not shown since it forms no part of the present invention. The particular construction of the combustion chamber 32 also forms no part of the present invention, but will be hereinafter described wlth the aid of Figs. 4 and 5 in which the combustion chamber is shown on a larger scale than in Fig. 1.

The manner in which the air and gaseous products of combustion circulate through the heater shown in Fig. 1 will be apparent from the various arrows applied to that figure. Outof-doors air, drawn into the heater through the pipe 20 by the motor-driven fan, cools the motor sufficiently to prevent excessive heating of it. The air supplied by the fan passes upwardly through the annular space between the casing 30- and the combustion chamber 32, and some of this air flows and seeps (as hereinafter described) into the combustion chamber 32, and some of this air passes upwardly, through the restricted opening between the top of the casing 30 and a lip extending downwardly from the manifold 48 intothe space within the manifold casing 46. The air entering the combustion chamber 32 is sufficient not only to support substantially complete combustion of the fuel, but to provide an excess of air which mixes with the gaseous products of combustion and passes upwardly out of the top of the combustion chamber ,32 into. the manifold 40 along with the gaseous products of combustion. In this way, the temperature of the mixture of gaseous products of combustion and air entering the manifold 40 is prevented from rising to an excessive value. In practice, this mixture of air and gaseous products of combustion may be in the neighborhood of 1200 F. Owing to the suction exerted by the fan 26 through the pipes 54, 52 and 50, a flow of air isiindu'ced from the top of the manifold casing 46,"with the result that air is drawn in through the hoods 62 into the annular spaces between the distributing pipes 42 and the encasingpipes 60; and air is also drawn in through the .openings 64 in the encasing pipes 60.. This suction effect of the fan may be regulated by means of the damper 5B; Thus it will be apparent that all-of the parts of. the heater, which are raised to high temperatures by contact with the mixture of gaseous products of combustion and air emerging from the combustion chamber 32, are surrounded by the casings 30 and 46 and by the encasing pipes 60. Therefore, there will be no fire risk resulting from a tobacco leaf dropping on any of the parts of the heater.

The form of the invention illustrated in Figs. 2 and 3 will now be described. It will be noted that this embodiment of the invention differs from the embodiment illustrated in Fig. 1 by the fact that the pipes 50, 52 and 54 (which in Fig. 1 connect the top of the manifold casing 46 with the fan casing) are omitted and the top of the manifold casing, is closed. Therefore, the functioning of the heater illustrated in Figs. 2 and 3 differs from the functioning of the heater shown in Fig. 1, in that air flows from the manifold casing outwardly instead of inwardly through .the annular spaces between the distributing pipes and the encasing pipes. In Figs. 2 and 3, like parts are referred to by the same reference characters as those employed in Fig. l, and a detailed description of those parts is unnecessary. The-cover which closes the top of the manifold casing 46 in Fig. 2 is shown at 92; and it will be noted that the arrows, which indicate the direction of air flow through the annular spaces between the distributing pipes 42 and the encasing pipes 60, point in a direction opposite to the arrows in those spaces in Fig. 1.

The manner in which the air and gaseous products of combustion circulate through the heater shown in Fig. 2 will be evident from the various arrows applied to that figure. In the heater of Fig. 2, the fan draws air from out-ofdoors through the pipe 20 in cooling engagement with the motor 22; and the fan also draws in barn air as indicated by the arrows at the left end of the. fan. The air thus supplied by the fan passes upwardly through the annular space between the casing 30 and the combustion chamber '32. Some of this air flows and seeps into the combustion chamber 32 where it supports the combustion of the fuel and also provides an excess of air which mixes with the gaseous products of combustion; and this mixture passes upwardly out of the top of the combustion chamber 32 into the manifold 40. The remainder of the air supplied by the fan passes upward1y,through the restrictedopening between the top of the casing 30 and a lip extending downwardly from-the manifold 40, into the space within the manifold casing 46, as shown by the arrows in Fig. 2; and this air flows outwardly through the annular spaces between the distributing pipes 42 and encasing pipes 60, along with mixed barn air which entersthe encasing pipes. 60 through the openings such as those shown at 64. Thatis, inthe heater of Fig. 2, the air flowing through the annular spaces between the distributingpipes 42 and the encasing pipes 60 passes out of the hoods (indicated at B2 in Fig. 1) instead of being drawn in through those'hoods as is the case in the heater of Fig. 1. In the heater of Fig. 2 (as in the heater of Fig. 1) all of the parts of the heater which are raised to a high temperature by the hot mixture of air and combustion gases supplied from the combustion chamber are surrounded by the casing 30, the manifold casing 46 and cover 82, and by the encasing pipes 60 thereby eliminating any fire risk resulting from a tobacco leaf dropping on any parts of the heater.

The heater embodying the invention which is illustrated in Fig. 4 will now be described; and the construction and functioning of the combustion chamber, which is the same in all three illus trated embodiments of the invention, will belater explained. In the heater of Fig. 4, the air is supplied by the fan 76 which is driven by the motor 78,- as in the heater of Fig. 2. The heater of Fig. 4 differs from the heaters of Figs. land 2 principally in the relative locations of theifan, combustion chamber and manifold. In theheatersof Figs. 1 and 2, the combustion chambere2 and its surrounding casing 30 are arranged between the fan 26 and'the manifold ill and its Surrounding casing 48, with the resultthat the air supplied by the fan flows through the casing 30 surrounding the combustion chamber 32 on its way to the casing surrounding the manifold. In the heater of Fig. 4,- however, the manifold 88 and its surrounding casing 82 are arrangedabetween the fan T6 and the combustion chamber 84 (hereinafter described) and its surrounding casing. 9i, with :the result that the air supplied by the fan 16 passesthrough the manifold casing 82- on its way-tothe casing 99 surrounding .the combustion chamber 84. It will also be ."notedthat in the heater-of Fig. 4 thecombustion chamber Sdvis invertedlin comparison with th'e arrangemcnt shown in Figs. 1 and 2) with the result that the gaseous products of combustion and dilutingair mixed therewith flow downwardly (instead of upwardly) from the combustion chamber 84:into the top of the manifold casing. instead of into the bottom of the manifold casing as in the heaters of Figs. 1 and 2. Referring now to the details of construction of the'heatershown in Fig. 4, it will be apparent that a pipe 88 extends upwardly from the fan casing andv communicates with a casing 89 which at its top is associated with the manifold casing 82; and that a casing 9| which .surrounds'the combustion chamber 86 and is provided with a top cover 92, is mounted.

on the topof the manifold casing 82.1 Extending uting pipes 93. As in the heater of Figs. 1 and 2, thedistributing pipes 93 are surrounded by encasing pipes at which are securedto the manifold casing 82. As will beapparent from Fig. 4, the construction of the manifold casing .82, where the encasing pipes as are connected toit,-is such that a restricted annular opening is provided through which air flows from the manifold casing 82 into the spaces between the pipes 93- and 9 1, as shown by the arrows. A cylindrical sheet metal wall 56 is, mounted between the casing 9i and the combustion chamber 84, for a purpose later described. As in the heaters of Figs. 1 and 2, the combustion chamber 84 of the heater shown in, Fig. 4 is pro.- vided with a fuel nozzle Hi connected to a fuel supply pipe I02 and is also provided with a spark plug Hi4 which is connected by a wire I06 to any suitable and well known ignition device.

The V manner in which the air and gaseous products of combustion circulate through the heater shown in Fig. 4 will be evident from the various arrows applied to that figure. As in the case of the heater of Fig. 2, the motor driven fan shown in Fig. 4 supplies both out-of-doors and barn air to the heater. This air flows upwardly through the pipe 88 and casing 89 into the manifold casing 82 from which some of the 1 airflows through the restricted annular openings into the spaces between the .pipes 92 and .4; and the rest of the air flowsupwardly through the annular space between the casing 9| and the wall 96, and then over the top of the wall 96 and into the annular space betweenthe wall 96 and the combustion chamber 84, from which this part of the air flows and seeps into the combustion chamber 84 as hereinafter described. The mixture of the gaseous products of combustion and diluting air passes from the combustion chamber 84 into the manifold 80 and then outwardly through the distributing. pipes 93. It will be understoodthatthedistributing pipes 93 at their outer endsimay/ be provided withdownwardly extending portions of the kind shown at :44 in Figs. land ,3; and the outer ends of the encasing pipes 68 may bep'rovided with hoods suchas' those shown at 52 in Fig. 1. In the heater. of Fig. 4 (as in the heater of Figs. 1 and 2) all of the parts of the heater which are raisedrto high temperatures by the mixture of air and gaseous products of combustion sup plied by the combustionchamb'er-Mare surrounded by cooler air which issupplied by the motor-driven fan, thus eliminating any fire risk if a tobacco leaf falls on-any-part of the furnace.

- The construction of the combustion chamber employed inthe three illustrated embodiments of the'invention will now be described. Since this combustion chamber is novel inconstruction I and'may' not be claimed in the presentapplication. it is the subjectof aseparate patent'application, Serial No. 73,411, filed January 28, 1949. The structureof thecombustion chamberywill be described with the aid of Fig. d because-it is there shown on a larger scale than in Figs; 1 and 2 and Fig. 5 will also be referred to. From Figs i and 5 it will be apparent that the entire cylindrical portion-of the combustion chamber is made of sheet metal which is perforated throughout its area with a large-numberof small holes H6 shown in Fig. 5. The primary purpose of these small holes lit) is topermit-air to seep through thewall of the combustion chamber and provide on its inside surface-alayer or cushion of air which I have discovered serves the highly useiulpurpose of preventingthe formation of a-oarbonaceous deposit on the inside of the combustion chamber. These small holes H0 also result in. a cooling of thecombustion chamber due to the air seeping through them. To the best of my knowledge and belief, it is novel to use such perforated sheet material for the making of a combustion chamber; :and 'I believe that I am the discoverer of the highly beneficial results-achieved bythe use of such perforated sheet material in the making of a combustion chamber. Furthermore, I have dis covered that the size of the holes 1 it in the wall ofthe combustion chamber has an important bearing upon theresults and advantages achieved. I'have found that the best results are obtained by employing for the making of the wall of the combustion chamber 22 gauge, type 310 .or' iafi stainless sheet steel which is perforated'with holes havingza diameter of approximately .036 of an inch and arranged with approximately 270-holes to the square inch. It will however be understood that gauge of the sheet steel, the diameter of the holes and the number of holes per square inch may vary somewhat from the figures just given, without sacrificing the advantages of my novel combustion chamber. The important thing is to make these holes lit so small and to arrange them so closely to one anotherthat air will seep through them intothe combustion chamber and will provide a cushion or layer of air on the inside of the. wall of the combustion chamber.- The much larger holes H2 (shown in Fig. 4) in the cylindrical walL of the combustion chamber 84, serve to admit to thecombustion chamber the air necessary to adequately support combustion of the fuel. and additional, air to dilute the gaseous productsof combustion which is considered desirable in the heaters described in this application. "While the inventionhas been, descr'ibedas embodied in tobacco-barn heaters, it will be understood (as mentioned at the beginning of this specification) that it may be embodied in heaters for supplying a mixture of hot air and gaseous products of combustion to an enclosed space of any kind. Of course, when the heater is used for some purposes, the distributing and encasing pipes may be omitted, for which reason these elements are not included in some of the claims hereto appended.

- What is claimed is:

- "l. A heater for supplying hot air to an enclosed space within which said heater is located,- comprising a cylindrical combustion chamber closed at one end and open at the other end and having in its cylindrical portion holes for admitting air, a casing surrounding said combustion chamber and spaced therefrom, a manifold directly connected to the open end of said combustion chamber to receive therefrom hot air and gaseous products of combustion, distributing pipes connected to and extending from said manifold and opening into said enclosed space to receive the hot air and gaseous products of combustion from said manifold and discharge same into said enclosed space, a casing surrounding and spaced from said manifold and communicating with the said casing which surrounds said combustion chamber, encasing pipes connected to and extending from the said casing which surrounds said manifold and surrounding and spaced from said distributing pipes, and a fan connected and arranged to supply air to the space within the said casing which surrounds said combustion chamber and to the holes in the combustion chamber and also to the space within the said casing which surrounds said manifold, a first air inlet to said fan comprising a pipe leading to said fan from outside said enclosed space, a motor located in said pipe substantially in line with the axis of said pipe and coupled to drive said fan, and a second air inlet to said fan communicating with said enclosed space to effect recirculation of heated air discharged from said distributing pipes into said enclosed space.

2. A heater for supplying hot air to an enclosed space within which said heater is located, comprising a fan, a casing arranged to receive air from said fan, a cylindrical combustion chamber supported within said casing and closed at one end and open at the other end and having in its cylindrical portion holes for admitting air, a manifold directly connected to the open end of said combustion chamber to receive therefrom hot air and gaseous products of combustion, distributing pipes connected to and extending outwardly from said manifold and opening into said enclosed space to receive the hot air and gaseous products of combustion from said manifold and discharge same into said enclosed space, a casing surrounding and spaced from said manifold and communicating with said casing within which said combustion chamber is mounted, encasing pipes connected to and extending from said manifold casing and surrounding and spaced from said distributing pipes, a first air inlet to said fan comprising a pipe leading to said fan from outside said enclosed space, a motor located in said pipe substantially in line with the axis of said pipe and coupled to drive said fan, a second air inlet to said fan communicating with said enclosed space to effect recirculation of heated air discharged from said distributing pipes into said enclosed space, and a duct connecting said manifold casing with the intake side of said fan; whereby combustion air is supplied by said fan to the space between said first mentioned-- casing and said. combustion chamber and also to the space between said manifold and its casing, and cooling air is drawn by said fan through the annular spaces between said distributing and encasing pipes and into said manifold casing.

3. A heater for supplying hot air to an enclosed space within which said heater is located, comprising a cylindrical combustion chamber closed at one end and open at the other end and having in its cylindrical portion holes for admitting air, a casing surrounding said combustion chamber and spaced therefrom, a manifold directly connected to the open end of said combustion chamber to receive therefrom hot air and gaseous products of combustion, distributing pipes-com nected to and extending from said manifold and opening into said enclosed space to receive the hot air and gaseous products of combustion-from said manifold and discharge same into said enclosed space, a casing surrounding and spaced from said manifold and communicating through a restricted opening with the said casing which surrounds said combustion chamber, encasing pipes connected to and extending from the said casing which surrounds said manifold and surrounding and spaced from said distributing pipes, and a fan connected and arranged to supply air to the space within the said casing which surrounds said combustion chamber and to the holes in the combustion chamber and through the restricted opening into the space within the said casing which surrounds said manifold and out through the annular spaces between said distributing and encasing pipes, a first air inlet to said fan comprising a pipe leading to said. fan from outside said enclosed space, a motor located in said pipe substantially in line with the axis of said pipe and coupled to drive said fan, and a second air inlet to said fan communicating with said enclosed space to effect recirculation of heated air discharged from said distributing pipes into said enclosed space.

4. A heater for supplying hot air to an enclosed space within which said heater is located, com prising a fan, a casing arranged to receive air from said fan, a cylindrical combustion chamber supported within said casing and closed at one end and open at the other end and having in its cylindrical portion holes for admitting air, a manifold mounted between the fan and combustion chamber within said casing and directly connected to the open end of said combustion. chamber to receive therefrom hot air and gaseous products of combustion, distributing pipes connected to and extending outwardly from said manifold through the wall of the first mentioned casing and opening into said enclosed space to receive from said manifold the hot air and gaseous products of combustion and discharge same into said enclosed space, encasing pipes connected to and extending from said firstmentioned casing and spaced from said distributing pipes, restricted openings beingprovided from said casing into said encasing pipes, a first air inlet to said fan comprising a pipe leading to said fan from outside said enclosed space, a motor located in said pipe substantially in line with the axis of said pipe and coupled to drive said fan, and a second air inlet to said fan communicating with said enclosed space to effect recirculation of heated air discharged from said distributing pipes int said enclosed space;

9 10 whereby air is supplied by said fan to said first UNITED STATES PATENTS mentioned casing from which it flows through Number a Name Date said holes into said combustion chamber and 1513598 Judelson Oct 28 1924 also through said restricted openings into the Lewis 1926 annular spaces between said distributing and 5 1:728053 Gm Semi 1929 casing pipes- 1,943,053 Boisset Jan. 9, 1934 CALVIN MACCRACKEN 2,072,731 Crosby Mar. 2, 1937 2,082,289 Hodgin June 1, 1937 REFERENCES CITED 2,095,186 Gill Oct, 5, 1937. The following references are of record in the 10 211101209 Engels 1938 m of t t t: 2,361,643 Mueller CD17. 31, 1944:

2,510,645 McMahan June 6, 1950 

